In the United States, cannabis products are now legally available for adult medical use in 30 states and the District of Columbia. Despite strict laws and federal and state initiatives to prevent cannabis distribution to and access among youth, the trends toward legalization and relaxed social norms have led to concerns over increasing adolescent use. Adolescent marijuana use has been associated with massive costs to society and linked to myriad negative health and legal consequences, school problems and lower income in adulthood, subsequent illegal drug use and drug dependence, and decreased cognitive functioning, with early onset marijuana users showing worse performance on cognitive tasks. This pressing problem has led states, institutions, and organizations to adopt regulatory policies and practices aimed to prevent adolescent marijuana use, but with questionable success. A major pathway for youth at risk for marijuana use to receive services is through state family and juvenile services programs and juvenile courts. Despite the development of evidence- based prevention practices for youth substance use, no marijuana-specific parent-based interventions have been developed for the current legalized marijuana environments that now challenge families in new and unique ways. More critically, juvenile court judges and JJS staff responsible for services, lack user-friendly, technology-based, cost-efficient resources to address the needs of families at risk for marijuana abuse. This Phase I SBIR research aims to address this urgent issue by developing a web-based early intervention prototype, ?Motivating Actions for Prevention? (MAP), for adolescent marijuana use for parents of at-risk youth involved in juvenile justice and child and family services programs. MAP will be formulated as a brief motivational approach with educational and skill-building components to address marijuana effects and misconceptions, safety and security, parent- adolescent communication, and other strategies to reduce youth exposure to risky conditions and foster resilience through family cohesion, positive modeling, and effective coping. The study aims are to: (1) Conduct focus groups with 20 parents to guide the development of MAP content, structure and delivery methods, integrating the formative feedback within the iterative development of the initial web-based prototype; (2) Create and evaluate an Alpha prototype and materials for the MAP intervention, including the online framework that contains the basic essential elements of text, graphics, and interactive features; (3): Conduct a pilot test of a Beta-prototype for the MAP intervention with an independent pilot sample of 40 parents of youth at risk for marijuana abuse, including parents with current medical marijuana use and parents of youth referred by law enforcement to the JJS, to examine functionality (e.g., technical errors) and feasibility (e.g., percent completions). The Phase I research is designed to yield an innovative prevention product that can be scaled to meet the growing demand among juvenile court judges, JJS staff, and others responsible for state and community prevention programming for effective, low-cost, widely accessible resource for states with legalized marijuana.